1,3,5-Trioxane (hereinafter “trioxane”) is the cyclic trimer of formaldehyde. Trioxane is mainly used as a starting material for the manufacturing of polyoxymethylenes (POM) which is a high performance polymer having desirable and exceptional properties in terms of mechanical, chemical and temperature stability. Polyoxymethylene polymers are available as homo- and copolymers.
As the polyoxymethylene market is growing, there is a desire on the side of the trioxane producers to expand their production capacities in order to satisfy the trioxane demand on a competitive basis. The major technical process for the production of trioxane is the conversion of aqueous formaldehyde solutions in the presence of concentrated sulfuric acid as a catalyst. The process for the production of trioxane known in the prior art is complex and comprises an extraction step which necessitates tedious solvent recovery steps. Furthermore, the process conventionally and commercially known in the prior art is time and energy consuming and leads to a low degree of conversion of the formaldehyde source into the desired cyclic acetals. Furthermore, the amount of side products formed by the process is high.
In view of the above, a need currently exists for an efficient process for producing cyclic acetals, such as trioxane. A need also exists for a process for producing cyclic acetals that has a relatively high conversion rate. A need also exists for a process for producing cyclic acetals from different formaldehyde sources.